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AD5940: External RTIA will be more accurate than internal RTIA with calibration? external oscillator?

Category: Hardware
Product Number: AD5940

Following up questions from my previous post: (1) AD5940: Offset on the current measurement. - Q&A - Precision ADCs - EngineerZone (


Yes.1% is the best accuracy achievable.

0.1% accuracy is not achievable in AD5940 if RTIA, DAC, internal references and internal oscillators are to be used.


I was wondering using external RTIA will be more accurate than using Internal RTIA with Calibration for internal RTIA?

And from my understanding, I am not sure why using external oscillators will improve accuracy as it is used for wakeup timer so it will only used for trigger sequencer periodically.

I did adjust period of wakeup timer(AmpODR ) for multiple phases voltage measurement, but it still works the same for current measurement accuracy under different periods.

float AmpODR;                 /* in Hz. ODR decides the period of WakeupTimer who will trigger sequencer periodically. DFT number and sample frequency decides the maxim ODR. */

Do you mind explaining more on external oscillators?

Appreciate for the help!

Added the product number to the subject field
[edited by: JEstayo at 1:11 AM (GMT -5) on 26 Feb 2024]